This serie of patches aims to reduce the usage of the
AioContexlock in block-copy, by introducing smaller granularity
locks thus on making the block layer thread safe.
This serie depends on my previous serie that brings thread safety
to the smaller API used by block-copy, like ratelimit, progressmeter
abd co-shared-resource.
What's missing for block-copy to be fully thread-safe is fixing
the CoSleep API to allow cross-thread sleep and wakeup.
Paolo is working on it.
Patch 1 provides a small refactoring, patch 2 introduces the
.method field in BlockCopyState, to be used instead of .use_copy_range,
.copy_size and .zeros.
Patch 3 provide a refactoring in preparation to
the lock added in patch 4 on BlockCopyTask, BlockCopyCallState and
BlockCopyState. Patch 5 uses load_acquire/store_release to make sure
BlockCopyCallState OUT fields are updated before finished is set to
true.
Based-on: <20210518094058.25952-1-eespo...@redhat.com>
Signed-off-by: Emanuele Giuseppe Esposito <eespo...@redhat.com>
---
v5:
* Squash patch 3 (improve comments) with patch 5 (add CoMutex).
* Better comments in block-copy, drop IN/OUT/State categories
* Remove some load_acquire in patch 6, replace them with atomic reads
Emanuele Giuseppe Esposito (4):
block-copy: small refactor in block_copy_task_entry and
block_copy_common
block-copy: move progress_set_remaining in block_copy_task_end
block-copy: add CoMutex lock
block-copy: atomic .cancelled and .finished fields in
BlockCopyCallState
Paolo Bonzini (1):
block-copy: streamline choice of copy_range vs. read/write
include/block/block-copy.h | 2 +
block/block-copy.c | 368 +++++++++++++++++++++++--------------
2 files changed, 231 insertions(+), 139 deletions(-)
--
2.31.1
